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Über dieses Buch

Connectivity has arrived in the vehicle - whether it is in-car internet or car-to-car communication. For the chassis too, the connected car is increasingly becoming a driver of innovation. Predictive and intelligent chassis systems and automated driving are just some of the topics being addressed. In addition to enhancing driving comfort and safety, interconnecting the powertrain with the chassis can also provide new functions, not only in cars but also in commercial vehicles. What is more, modularization, electrification of the powertrain, intelligent development methods and efforts to reduce fuel consumption are also driving innovations in chassis systems.

Inhaltsverzeichnis

Frontmatter

The all new BMW 7 Series

Improvements in driving characteristics can be seen with each vehicle generation throughout the automotive sector. A high level of quality and constant improvements in handling, comfort, and safety combined with reductions in the levels of CO2 emissions are expected by the customers.

Peter Langen, M. Wachinger, C. Dorrer, W. Nixel, M. Schwarz

Highly automated driving for commercial vehicles

Highly automated driving is a further decisive step towards accident-free driving based on intelligent interaction of driving assistant systems, which in turn will result in increased road safety. In addition, this concept will reduce the stress to which drivers are subject and increase their comfort level in monotonous traffic situations (e.g. long stretches of highway driving or stop-and-go situations), provide greater efficiency and economy and contribute to ecological sustainability. The Future Truck 2025 has now demonstrated for the first time how much freedom for new tasks can be created in the logistics field, even while the vehicle is in motion, to improve the working environment of truck drivers. This shift of emphasis from being “just” a driver to being a transport manager offers enormous potential, but is accompanied by a new kind of driver/vehicle interaction.

Markus Kirschbaum

Automated driving, electrification and connectivity – the evolution of vehicle motion control

Looking back at the last 50 years, driving a car was a completely different experience than today. In the 60’s and 70’s power steering was limited to expensive hydraulic systems on only the most expensive cars. Through much of the 80’s, smaller cars like the Fiat Panda, VW Golf and Renault Rapid were manufactured without power brakes. In other words, the driver had no assistance in powering and controlling the brake and the steering system.

Alexander Häußler

Future consumer protection demands on vehicle safety

This manuscript is not available according to publishing restriction. Thank you for your understanding.

Andreas Rigling

Model-based development methods – What can chassis and powertrain development learn from each other?

The biggest challenge for today’s vehicle development is the increasing number of vehicle variants for different markets, which have to be developed in ever shorter cycles. In addition, customers and governments have high demands when it comes to comfort, driving pleasure, consumption, security and CO2 emissions. The powertrain and the chassis domain have developed their own methods to solve these difficulties. Although there are some important differences, the question arises how one domain can profit from the methods of the other domain. For example, the strict emission legislation in the powertrain sector lead to advanced model-based calibration and testing methods, which could be useful also for other domains.

Bernhard Schick, Michael Paulweber

The chassis of the all new Audi Q7

High customer expectations in growing markets worldwide have set a challenging task for the chassis development of the Audi Q7. Not only is it supposed to offer the typical driving dynamics of an Audi, but also the goal was set to offer best in class comfort in order to provide a luxurious ride, especially for long distance trips. Besides these objectives, the chassis also has to contribute to achieving the CO2-emissionlimits implemented by governments around the world. Finally, the vehicle stability is to be ensured during critical manoeuvers, since rollover is an issue with Sports Utility Vehicles (SUV) in general.

Carsten Jablonowski, V. Underberg, M. Paefgen

Network topology for chassis – potential of ethernet-based systems

The increasing number of functions in modern vehicles like automobiles induces an increasing number of information to be interchanged between the diverse electronic control units (ECU) in the vehicle. Modern systems, like advanced driver assistance systems or infotainment systems, demand broadband communication channels. Beside the traditional bus systems, like CAN, MOST or FlexRay, Ethernet becomes more and more important for the in-vehicle data interchange, too.

Kristian Trenkel, Patrick Wunner

Suspension design of the Visio.M electric research vehicle

“Electric vehicles powered by electricity from renewable energy sources are an attractive option for mobility within the urban area and beyond. However, previous approaches lead to vehicles that either are too heavy and too expensive or do not meet mass-market safety requirements. Within the joint research project Visio.M scientists at the Technische Universität München (TUM) in cooperation with engineers from the automotive industry, have developed a concept to produce electric cars that are efficient, safe, and inexpensive. The project had a total volume of 10.8 million euros and was funded by the German Federal Ministry for Education and Research (BMBF)” [Vis15].

Andreas Schultze, Thorsten Helfrich, Markus Lienkamp

Development of an active motion system of tire contact point control

This paper presents the possibilities of a direct wheel control system, which can optimize both cornering performance and turning radius. Tire contact patch position and toe angle can be controlled independently for the front wheels at both left and right hand sides using a robotic suspension system. Quasi-trivial modes such as different configurations of track width or wheelbase lead to a reduction on roll angle and weight transfer. A fully independent wheel control enables further a much more powerful cornering performance control. This paper describes the initial investigations on performance prediction.

Hiroshi Shibuya, Hiroo Iida, Hiroyuki Kanayama, Daigo Fujii, Xabier Carrera Akutain, Kotaro Shima

The influence of the modeling depth of active chassis systems with respect to the development stage and their interaction with driving characteristics

Active Chassis Systems (ACS) cause perceptible driving characteristics or help to maintain driving stability even in precarious situations. Their use enhances driving agility and comfort. The development of such systems needs to be well coordinated with the development process of the full vehicle. During different stages of the latter, knowledge in different extent needs to be achieved and transferred between manufacturers of the actuator system and the car. In terms of vehicle dynamics, top level system characteristics are of utmost importance even in early stages. A proper way of simulative representation by simple models is presented. With ongoing development, further insight into the actuator in terms of energy demand and occurring dynamic states (forces, torque) is necessary to develop connected subsystems such as power supply or axes of the final vehicle. Different degrees of abstraction for simulative representation are presented here as well. An exemplary study regarding the influence of parameter variation and modelling depths is given.

Kilian Dettlaff, Jochen Wiedemann, Uli Schaaf, Ingo Scharfenbaum, Andreas Wagner

Smart electromechanical system to improve vehicle handling and stability by toe and camber control on the rear wheel

The challenge to enhance the vehicle driving and handling with a state estimation and prediction system is presented by fusing a real time vehicle model capable of providing a good indication of vehicle stability and control, and a secondary model able to estimate the vehicle state from real sensors to correct the indications of the primary model.

Isabel Ramirez Ruiz, Marc Alirand, Nicolas Kieny, Federico Cheli

Tire use and road safety – background to policy recommendations for new EU measures

TNO and TML performed a study commissioned by the European Commission regarding what measures on a European level can be taken in relation to the use of tyres to improve road safety. The study considers the use of Winter tyres, tread depth requirements, tyre inflation pressure maintenance and tyre ageing effects and damages. An assessment has been made of the tyre safety performance, current use of tyre and consumer awareness, tyre related accident statistics and existing regulations for the different tyre aspects (including TPMS). Results from analyses on accident records from Germany (GIDAS) and a NHTSA study provide estimation of safety benefits. Policy options are defined and estimations are made of the accident reduction on a European scale to assess the monetary benefits, which are compared to the associated cost of execution of the policies. The results indicate that extended enforcement of tread depth regulation and increase of tyre pressure maintenance are most cost effective. For Winter tyres it is cost effective to introduce a harmonised definition using the 3PMS performance criterion, and installing a dedicated tread depth requirement of 4 mm would be around break even. Promoting the use of Winter tyres, or extending the enforcement of the use of Winter tyres may not be cost effective as a policy option, however the estimated safety benefit is significant (i.e. 3 % reduction in the number of fatalities during winter conditions). Installing a harmonised tread depth for truck tyres, and organising tyre inspections between periodic vehicle inspections are expected to be beneficial.

Sven Jansen, Antoine Schmeitz, Lars Akkermans

The influence of wheel and tire aerodynamics in WLTP

The geometric shape of passenger car wheels can have a large influence on the aerodynamic drag of a vehicle as it has been shown already in different publications. In combination, tire and rim cause approximately 25% of the overall drag. Until now, the challenge for aerodynamicists is to find the rim / tire combination with the best aerodynamic characteristics, which then is used for the official cD-value of the vehicle and for the determination of fuel consumption according to NEFZ regulations.

Felix Wittmeier, Timo Kuthada

Towards a comprehensive approach for the sustainability assessment of a product: product social impact assessment

The importance of sustainability assessment along the product life cycle is getting more significant in companies and the scientific community. The BMW Group uses life cycle assessment (LCA) as tool for improving the environmental performance of its products. The definition of a sustainability assessment of a product life cycle says that three dimensions should be evaluated: environmental, economic and social.

Marzia Traverso, Peter Tarne, Volkmar Wagner

A vehicle lateral control approach for collision avoidance by emergency steering maneuvers

Many accidents lead back to the driver. It is assumed to be beneficial that driver assistance systems and/or automated driving functions ease tension off the driver or release him from the task of driving in order to reduce traffic fatalities. The development of driver assistance systems started with ABS (Anti-Lock Braking System) in 1978, TC (Traction Control) in 1987 and ESC (Electronic Stability Control) in 1995. These systems are known for their contribution on the reduction of traffic fatalities over the last years. But still far too many cars crash every day. The aforementioned systems do not take environmental information into account, which limits the collision avoidance potential. A system that senses its environment by radar and/or camera sensors is the AEB (Autonomous Emergency Braking) which is supposed to further reduce the amount of accidents in the future as the take rate increases. Although assisting the driver in emergency situations by braking is beneficial in some situations, it also has its drawbacks. The problem is that emergency braking can only be initiated if the obstacle is detected for sure. Nowadays sensors can only provide limited safe ranges. This means that at typical highway speeds the collision with a stationary obstacle can only be mitigated by braking. A swerving maneuver is a viable alternative to braking or the combination of both if the required space is not occupied by other obstacles. The emergency steering maneuver offers the advantage that the last-point-to-steer is even closer to the obstacle than the last-point-to-brake with growing vehicle speed, which yields a higher collision avoidance potential. The disadvantage is that the maneuver is far more difficult than full braking. A subject study [1] in a driving simulator has proven that the average skilled driver is not capable of steering the vehicle properly around obstacles in the majority of occasions. This is why an advanced driver assistance system (ADAS) is useful that supports the driver by steering torque overlay and, as an option, by braking interventions. The improvement on the collision avoidance behaviour of the driver has been proven by the authors in the aforementioned study [1].

Martin Keller, Carsten Haß, Alois Seewald, Torsten Bertram

Collision avoidance with combined braking and steering

Among various driver assistance systems with environmental sensors the first emergency braking systems are available. To avoid collisions with a vehicle driving in front of the own vehicle also an evasive maneuver is possible to avoid the collision. Particularly at higher velocities this maneuver is characterized by a later intervention time.

Carlo Ackermann, Jakob Bechtloff, R. Isermann

Driver assistance for trucks – from lane keeping assistance to smart truck maneuvering

In June 2013 Bosch Automotive Steering introduced with the Servotwin the first electro- hydraulic steering system worldwide for heavy commercial vehicles. The Servotwin represents the innovative combination of a recirculating ball power steering gear Servocom with an electronic drive and control unit (see Figure 1). Now for the first time already proven EPS steering functionalities from passenger cars are available in the commercial vehicle sector, e.g. active return for smooth mid position alignment.

Alexander Gaedke, Roland Greul, Stefan Kanngießer, Nicolas Boos

Development of a driving dynamics-oriented suspension design during the early concept phase

During the initial phase of concept development, the goals for suspension design are generally limited to achieving certain kinematic and elasto-kinematic characteristic curves. The evaluation of the resultant vehicle dynamics characteristics generally takes place at a later stage. The tools as well as tool chains, which are typically used for evaluating the influence of suspension parameters on driving dynamics, are expensive in terms of time, required effort and computing power. Also nonconformity with desired goals at a later stage may result in additional investment of time and effort in large magnitudes for the corrective measures leading to an unnecessary prolongation in the development process. Thus, being able to directly evaluate the influences of suspension kinematics on vehicle dynamics during concept phase, and optimise either the suspension characteristics or suspension parameters based on the vehicle dynamics requirements would result in a shorter and more cost effective development process.

Karthik Vemireddy, Torben Dittmar, Lutz Eckstein, Lars Hesse, Peter Rettweiler

Development of a chassis model including elastic behavior for real-time applications

For the prediction of the dynamics of vehicles, various mathematical models have been used successfully for many years. The complexity of these models ranges from very sophisticated to rather straightforward approaches. The right to exist for simple models often results from the need for short computation times due to many iterations associated with optimization tasks or even from real-time applications. If the models are to be used as part of driving dynamics control systems these computations have to be performed on ECUs affordable for series applications.

Frédéric Etienne Kracht, Yihai Zhao, Dieter Schramm, Benjamin Hesse, Michael Unterreiner

Lightweight design in subassemblies with changing design spaces to find an overall weight optimum for series-produced cars

A car needs to fulfill an enormous number of requirements. A production car cannot be developed by a single team therefore it is necessary to split the car into different assemblies such as body, axle carrier or engine. These assemblies are processed by different teams. The requirements of the complete car need to be translated into different specification sheets for the assemblies. In this way the teams are able to work efficiently and independently between the synchronization points. Each team creates a concept model and analyzes the properties with the goal to fulfill the requirements. At the synchronization points the properties are analyzed for the complete car. All deviations to the requirements are recorded and set to a list of points respectively a lightweight strategy. The responsible assembly for these points is subjectively identified by experienced engineers. After some iterations all requirements are fulfilled.

Gerhard Steber, Roland Lachmayer

Objektive Ratingmethode für Handling- und Komfortkriterien für den Einsatz im Fahrversuch und in der Simulation (Objective method for rating ride and handling criteria in simulation and vehicle testing)

Die AVL List GmbH beschäftigt sich in Kundenprojekt im Rennsport und im Serienfahrzeugbau seit vielen Jahren mit der Optimierung von Fahrwerkssystemen hinsichtlich Performance, Handling und Fahrkomfort. Im Rahmen dieser Tätigkeiten galt und gilt es, Methoden anzuwenden die die Qualität der Funktion eines Fahrwerks wiedergeben. Ist diese im Rennsport meist einfach über die Rundenzeitdifferenz darstellbar, stellt sich die Anforderungen im PKW Bereich komplexer dar, da hier in der Abstimmung ein Kompromiss aus agilem Handling, Fahrstabilität und Fahrkomfort gefunden und bewertet werden muss.

Joachim Ecker, P. Schöggl, E. Bogner, M. Oswald

Virtual chassis tuning with emphasis on the damper characteristics – a method for optimal integrative damper adjustment by means of vertical and lateral dynamics simulation and evaluation criteria

Vehicle suspension design is primarily characterised by conflicting targets concerning ride comfort, demanded handling performance qualities and save driving. Recent developments in the field of active and semi-active vehicle suspensions – aiming to dissolve these conflicts as far as possible – derive both from technological innovation as well as from corresponding theoretical studies. Although many active systems have been introduced to premium cars in recent years, the importance of well-designed passive systems is likely to remain for the foreseeable future, in particular for economyclass vehicles.

Florian Klinger, Johannes Edelmann, Manfred Plöchl, Stefan Jeindl, Bernhard Angrosch

Importance of body rigidity in the transient stage of the maneuver

Several studies have been performed underlining the importance of body rigidity for full vehicle performance, using a numerical/simulation approach (see [1] and [2]), a test-based approach ([3], [4] and [5]) or a combination of those ([6] and 7]).

In the studies where a body evaluation is performed to identify possible body weakpoints or the improvement potential – this is mostly done based on the body deflection in the steady state part of handling maneuvers.

In this paper, the focus is on the influence of body rigidity on the vehicle performance in the transient stage of the maneuver. A comparison of the results in the transient stage with those in the steady state part of the maneuver shows that different body stiffness characteristics are important in the transient stage compared to the steady state.

Charlie Gagliano, T. Geluk

Contribution to the objective evaluation of roll dynamics

In the early phase of the automotive development, the basic design of a vehicle defines the desired driving behaviour of the future series-production vehicle. The process relies mostly on simulation tools and experience from predecessor models, mainly because no physical vehicle models exist at this stage of the development.

Andreas Apfelbeck, M. Schwarz, S. Wegner, R. Henze, F. Küçükay

Improved prediction of ride comfort characteristics by considering suspension friction in the automotive development process

Ride comfort of passenger vehicles is affected by several subsystems and their properties. For reaching specific objective ride comfort targets the suspension is able to influence the response of the body in a wide range. However, the characteristics of the subsystem have not been fully investigated. In the following research the static and dynamic characterization of a suspension is conducted. For this purpose, especially friction properties are in the focus, not being established in conventional multi body models for simulation of ride comfort. A methodology for determining the dependencies of friction of multiple parameters is depicted and corresponding results are shown. Additionally the dynamic response under different conditions is analysed. The results are evaluated and procedures for considering and obtaining required properties in the development process are given. On the basis of this study the definition and parameterization of simulation models in development of vehicle properties can be improved, providing new potentials for reaching specific ride comfort targets.

Christian Angrick, Günther Prokop, Peter Knauer, Andreas Wagner

Endurance tests of electronic suspension for motorcycles – a system approach

A test method for electronic suspensions for motorcycles has been developed and introduced in the industrial practice. This method bases on 2 poster rig tests using vehicle independent laser scans of road sequences. The motorcycle was fixed onto the 2 poster with several restraints. A failure detection check was developed to test the function of suspension and sensor. Suspension strokes and body accelerations measured at the 2 poster agree very well with independently measured road test data. Applications of this method are pointing towards operational strength of the semi-active suspensions, comparison between different suspension systems and testing of sensor malfunction.

T. Kuttner, Frederik Harnischmacher

Availability and fail-safety approaches for electric power steering systems – trends and requirements

The market for passenger car steering systems has more or less completely changed from Hydraulic to Electric Power Steering (EPS) systems in the recent years. This change in technology also changed the safety requirements for steering systems significantly.

Eberhard Kübler, Thomas Pötzl, Thomas Frenz, Jürgen Sauler

Innovative software functions to operate electric power steering systems in sports cars – Unterstützungskraftregelung (UKR)

When using electric power steering systems in sports cars there are additional requirements concerning steering feel and road feedback. Here off-the-shelf steering mechanics quickly maxes out. Also the software of many manufacturers of steering systems does not entirely cover these requirements. To fulfil these requirements, regardless of the steering system supplier, Porsche has developed an own control approach to increase road feedback as well as additional software modules for optimized tuning ability of steering feel.

Anton Uselmann, K. M. Krüger, Christoph Bittner, G. Rivera

Steering System Fingerprint – a tool for steering system performance check and overview

Since more than 15 years Vehicle Dynamics is a key attribute defining the character of Ford vehicle, starting in Europe with the first generation Ford Focus, Ford Puma and Ka in the late 90th. Key driver to get this character consistent into the vehicles was in the first step a common understanding about the way the character should look like and how trade-offs between the sub-attributes, especially between steering / handling and ride needs to be set.

Frank Esser, T. Vercammen

Model-based steering ECU calibration on a steering-in-the-loop test bench

Modern electric power steering (EPS) systems allow a flexible adaptation of the same steering hardware to different vehicle types by calibration of the corresponding control unit (ECU). As the steering behavior is one of the major factors influencing the end customers` buying decision and driving experience, the steering ECU calibration has to fit very well to the customer requirements. A growing number of functions in the steering ECU offer increasing possibilities to influence comfort, safety and steering feel and must be validated in different driving maneuvers (figure 1). However, several trade-offs of these characteristics have to be solved such as the driver’s steering effort vs. the steering feedback while cornering.

Hans-Michael Koegeler, Bernhard Schick, P. E. Pfeffer, Alessandro Contini, M. Lugert, T. Schöning

Test infrastructure for EPS steering systems – balancing between requirement-based, experience-based and free testing

Based on the increasing introduction of electric and micro processor technology during the last decades – not only in automotive industry – systematic analytical testing of software (SW) is developing as an independent & autonomous acting engineering discipline. These activities are embedded in the product development life cycle and mainly support the product release process.

Thomas Maur

Realistic dynamic testing of EPS motors and ECUs by means of a hardware-in-the-loop test bench

Conventional test benches with real steering mechanisms often have non-negligible parasitic properties and multiple control systems to apply stimuli. As a consequence the EPS motor and ECU interact with a system that has a different dynamic behavior than the steering mechanism in the vehicle. Depending on the actual test scenario, this might reduce quality of testing results significantly.

Hermann Briese, Emad Farshizadeh, Stefan Oedekoven, Thomas Schubert, Hermann Henrichfreise

A simulator study on the controllability of steering systems with reduced maximum steering wheel angle

Active Front Steering shows that with a variable gear ratio, it is possible to reduce the maximum steering wheel angle from zero position to lock to approximately +- 360°. Compared to a conventional power steering system, this is a reduction of about 40%. With technologies like reliable electric power steering or steer-by-wire coming to the market, it is possible to reduce the maximum steering angle even further. To assess the controllability of further reduced maximum steering angles, a driving simulator study with two different steering systems with reduced total steering wheel angle is conducted with 36 experienced normal drivers. The steering systems are modelled within Matlab/Simulink and are integrated into the simulator on a real time target. The steering wheel is controlled by a synchronous AC motor providing up to 24 Nm of steering wheel torque. One system is an adapted conventional steering system without variable gear ratio and a maximum steering wheel angle of +- 180°. The other system employs the advantages of a steer-by-wire system and uses a PID-controller to regulate the vehicles yaw rate proportional to the steering angle. The steering wheel torque is proportional to yaw rate, lateral acceleration and vehicle velocity. The maximum steering angle is set to +- 90°. Both systems are benchmarked with a conventional steering system with a steering wheel travel from zero to lock of +- 600°. For all three systems subjective measurements to evaluate the steering feel and objective measurements, e.g. lane keeping quality to evaluate the controllability, are taken. The study shows that there is a limitation regarding the reduction of the steering wheel stroke between +-180 and +-90°, as the system with a maximum steering angle of +-90° performs worst regarding overall controllability. Furthermore it showed that the system with a limited maximum steering angle of +-180° performed best with respect to subjective steering feel.

Christian Dreßler, Stefanie Eßers

Implementation and testing of different control strategies on a steer-by-wire research platform

The progresses in computational speed and robustness made over the last decade by the automotive industry with respect to the automatization of road vehicles, reanimates the discussions about autonomous driving and X-by-Wire systems. ThyssenKrupp Presta AG has built up a modular research vehicle and equipped it with a Steer-by-Wire system in order to investigate the requirements and challenges that come along when the mechanical connection between steering wheel and steering rack is missing. In this paper, the architecture and concepts of the vehicle are presented and an overview about possible steering feedback strategies is given. Focus of the paper, however, is the adopted nonlinear position control of the steering rack, that is able to handle parameter variations, disturbances and sudden road condition changes while still guaranteeing an asymptotic tracking error convergence in an improved manner when compared to sliding mode compensators.

Michele Sigilló, Markus Dold, Claudio Delmarco, Kristof Polmans

Driving quality optimization based on cross-linked cause and effect chain models using the example of energy-efficient steering assistance

This paper addresses the time- and information-intensive task of calibrating an electric power steering assistance system, which is optimised for energy efficiency and can be adapted to different vehicle variants. Hereby, the focus is on determining the customer-perceived properties steering feeling, energy consumption, system price and market availability date. It will be demonstrated how this aim can be achieved with a reduced testing scope by automated generation of behaviour models that predict the system behaviour in the defined parameter range.

Marinette Iwanicki, Mohanad El‑Haji, Thomas Freudenmann

The consequences of a closed rim design for the brakes of a high-efficiency vehicle

Highly efficient and especially electrified passenger vehicles labor to expand the CO

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reduction or driving range through many measures. One significant factor is the optimization of the aerodynamics. The wheel rim design of a vehicle has a noticeable impact on the drag coefficient (c

d

) of a passenger vehicle.

Ralf Stroph, Sebastian Gielisch, Alfred Pruckner

The contribution of brake emissions to the total vehicle emissions

Over the last decades, the automotive industry has made huge efforts to lower vehicle emissions which have especially contributed to improve emission level in inner city areas. In Europe, limitations for particle emissions from diesel engines have dropped by 97% during the last two decades. In addition, friction materials have undergone many changes and functional components with an associated health hazard potential have been substituted step by step. Currently, the substitution of copper and its compounds have caused huge amounts of development work and resources in the friction industry dedicated to solve this challenge. However, with regards to a continuously further concentration of traffic in urban city areas, further measures and restrictions are to be expected. And although the exhaust emission values from vehicles is at an extremely low level, fine particle measurement devices in the inner cities still show there is room for improvement.

R. Steege, D. Welp, Jürgen Lange

An innovative production method for a C/C-SiC brake disc, suitable for a large-scale production

The industrial progress and the market-oriented management concepts result in increasing demands of the industry for improved performances while simultaneously improving on the energy efficiency. This results in the necessity for a progressive implementation of high-performance materials in areas such as the automotive industry, engineering, as well as applications in aerospace industry. Especially construction elements taking on large stresses call for excellent mechanical properties even at extremely high temperatures. In these high-temperature ranges only engineering ceramics, which unfortunately are very limited regarding the application due to the very brittle characteristics, showcase sufficient strength values.

Daisy Julia Nestler, N. Nier, K. Roder, A. Todt, B. Wielage, G. Wagner, L. Kroll, E. Päßler, S. Spange, J. Weißhuhn, H. Würfel

Combined control strategy for the combustion engine and brake system to enhance the driving dynamics and traction of front-wheel-drive vehicles

In very dynamic situations vehicles with front wheel drive can have certain limitations in terms of traction and handling characteristics. Because of the shift in dynamic wheel load from the front axle to the rear axle and the additional reduction of contact force of the inner front wheel when accelerating out of bends, the traction and handling capabilities can be limited.

Daniel Killian, S. Fischer, Markus Lienkamp, Stephan Poltersdorf, M. Schwarz

Real-time simulation of braking interventions in heavy commercial vehicles

Increasing efficiency, safety, reliability and comfort of vehicles is a crucial task in the commercial vehicle industry. Considering the wide range of possible vehicle applications, it is obvious that commercial vehicle manufacturers deliver a wide range of vehicle variants to meet customer’s needs. Offering a full range vehicle portfolio can lead to more than 50.000 chassis variants differing in axle configurations, wheel bases, suspensions, engine and gear specifications, cabin sizes, and fuel tank options, to name only a few [8]. Fulfilling high quality standards leads to an increasing development and testing effort that can be supported by virtual methods to optimise development process efficiency. Some examples of MAN and NEOPLAN products can be found in figure 1.

Philipp Wagner, Florian Bauer, Thomas Ille, Christian Kohrs

Efficient digital development of brake components with multiple requirements

This paper is addressed on efficient digital development on the example of brake components using TOKEN, a tool developed at TWT GmbH in Stuttgart. The main features of TOKEN are explained and an insight on how to use the tool is given. To demonstrate the potential of the software it is shown how TOKEN can be integrated e.g. in the development of a brake dust shield. In doing so it is presented how TOKEN can be used to provide additional information about aero- and thermodynamics in a defined design envelope. We present how this knowledge is able to lead to a more mature concept of a brake dust shield in the early development process. The maturity of the concept is verified in a detailed three-dimensional coupled CFD based analysis of the design and a comparison to an already existing brake dust shield.

Konrad Meister, Tobias Rößler, Victor Fäßler, Stefan Staudacher

Electrically controlled parking brake (EPB) for heavy commercial vehicles

This manuscript is not available according to publishing restriction. Thank you for your understanding.

Falk Hecker, T. Weinhold

Electric parking brake meets drum brake – synergy or contradiction

This manuscript is not available according to publishing restriction. Thank you for your understanding.

Christian Breiten, B. Schmittner

Large aircraft landing gears – a brief overview

The presentation provides a simple view on large aircraft landing gears. Following items are touched:

Landing gear types, civil, military and special ones are shown with several examples of existing and past lay outs.

The landing gear design objectives along with its constraints are given as well and discussed.

Surprising is the large run time of aircraft on ground which is expressed by typical usage.

An important item worth to mention is the weight relation of landing gears in relation to the total structure weight of an aircraft.

A short view on the airworthiness requirements is made which also provides a view on the suspension modeling for design load determination which is briefly expressed.

Landing gear overall structure components with their specific parts e.g. main fitting and shock absorber, braking system and retraction system are shown for nose and main landing gears.

Tyre for landing gears and their characteristics are discussed. Since aircraft tyre data are insufficient supplied by the tyre manufacturer special test bench has been developed and are successfully applied for structure design data. Some data and results are discussed.

Some of the landing gear structure loads conditions as are landing, braking and handling on ground are given.

If time allows, some interesting videos will be shown, providing an impression of dynamic landing impacts with excessive deformation at wheels and structure which indicates the enormous load at landing gear and associated airframe structure.

Hans-Martin Besch

Continuous wheel force measurement for passenger vehicles and commercial vehicles

This manuscript is not available according to publishing restriction. Thank you for your understanding.

Manfred Kraus, M. Bäuml

Adaptive state observers for driving dynamics – online estimation of tire parameters under real conditions

Model based control of lateral vehicle dynamics needs accurate tire models and their parameters to work efficiently. Tire properties are changing, due to wear, tire pressure, road conditions or a change in tire type or brand. Therefore the goal is to estimate the variable properties online by using the available ESC sensors only.

Jakob Bechtloff, Carlo Ackermann, R. Isermann

Damage on alloy wheels for motor vehicles – limits of rework

Thomas Kollmeier

Evaluation of different modeling approaches for the tire handling simulations – analysis and results

In the last years the need of more accurate vehicle handling simulation is increased. This is due to the wider possibilities that the new CAE methods offers to the vehicle dynamic engineers. In the past the semi-empirical tire models have been the most used, but today it seems to be not enough. In vehicle handling simulation more component become to be important like 3D road, thermal effect on rubber, asphalt conditions and electronic safety systems interaction with the tire dynamic. The cited semiempirical tire model seems to be not adequate to simulate such complex scenario also if they remain still attractive for a group of simulations scenario due to their simplicity and efficiency.

Francesco Calabrese, Manfred Bäcker, Axel Gallrein

Rolling resistance modeling for electric vehicle consumption

Due to increasing oil shortage and ever stricter CO

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-Emissions regulations vehicle energy consumption simulations are nowadays indispensable for the car industry. Especially the limited range of today’s electric vehicles makes it particularly necessary to model all energy loss sources as precisely as possible. As the drive train efficiency of electric vehicles is higher than those of conventional vehicles, the percentage of the energy loss caused by driving resistance forces is higher, too. These are composed of the aerodynamic drag, inertial drag, friction in the power train, rolling resistance force and slope resistance.

Andrea Ficht, Markus Lienkamp

The non-steady-state tire model as a set of physical submodels for driver assistance systems analysis

The challenges of advanced driver assistance systems development bring a necessity to describe a complex tire motion, which incorporates non-steady-state rolling, combined slip and a whole range of slip up to 100%.

Pavel Sarkisov, Günther Prokop, Sergey Popov

Evolution of the requirements on vehicle tires and insights from 15 years of test operation

40 years ago some scientists and engineers worked on ideas with cars that are riding on an air cushion and they assumed the function of wheels mounted on cars in the “future” (i.e. year 2000) would maybe just consist in supporting shunting and parking manoeuvres /1/. The future technology of tires was not considered at all.

Lars Netsch, Michael Staude

Concurrent design of vehicle tires and axles

Concept design of both axles and tires is difficult, because they simultaneously affect many different objective quantities in vehicle dynamics related to, e.g., self-steering behavior, transient behavior, maximum lateral acceleration, etc. Typically, the tire performance is evaluated using a specified axle design (or vice versa) and then optimized. This way, the optimal tire will depend on the axle that was chosen. If the axle design changes during the development process, the vehicle performance will suffer. Similarly, the optimal tire or axle for one vehicle may not be sufficient for another vehicle from the same platform or vehicle architecture.

Jens Wimmler, Dieter Schramm, Martin Wahle, Markus Zimmermann

New testing technology to evaluate lateral ice performance of tires

To drive with a vehicle on an icy road surface with standard winter tires (non studded) is due to the low friction potential one of the most critical driving situations appearing in the winter season. To lower the risk for accidents it is necessary to develop tires with increased ice performance. To do so reproducible test methods to evaluate tires potential to transmit forces on ice are necessary. Driving in an ice circle to evaluate the lateral force transmission of tires on ice is a difficult test procedure and its reproducibility can be improved. The newly developed test method is coupling a normal vehicle to a guiding rail and enables the measurement of lateral forces in dependency of the side slip angle of the tires. The new method is highly reproducible and correlating to the ice circle measurement procedure. Not just getting an average lap time to drive in the ice circle, but complete lateral force characteristics is a big benefit of the new test method enabling the tire developers to build up further knowledge about the force transmission of tires on ice, but in future to increase the friction potential even more.

Klaus Wiese, Jens Heyne, Burkhard Wies, Thomas Neddenriep

Sense-Plan-Act – the role of chassis systems

This manuscript is not available according to publishing restriction. Thank you for your understanding.

Ralph Lauxmann

Consumer acceptance ensured through safety

As automotive technology has advanced rapidly, safety has joined comfort and performance as one of the key requirements. Analysis and functionality testing of all safety components throughout the vehicle service life play a central role in this context.

Klemens Schmiederer
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Und alles läuft glatt: der variable Federtilger von BorgWarner

Der variable Federtilger von BorgWarner (VSA Variable Spring Absorber) ist in der Lage, Drehschwingungen unterschiedlicher Pegel im laufenden Betrieb effizient zu absorbieren. Dadurch ermöglicht das innovative System extremes „Downspeeding“ und Zylinderabschaltung ebenso wie „Downsizing“ in einem bislang unerreichten Maß. Während es Fahrkomfort und Kraftstoffeffizienz steigert, reduziert es gleichzeitig die Emissionen, indem der VSA unabhängig von der Anzahl der Zylinder und der Motordrehzahl immer exakt den erforderlichen Absorptionsgrad sicherstellt.
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AVL analysiert im Serien Batterie Benchmark Programm als neueste Fahrzeuge den Jaguar I-Pace und den Hyundai Kona

Das AVL Battery Benchmarking Programm analysiert auf Basis unterschiedlicher Faktoren die Wettbewerbsfähigkeit von Großserienbatterien. Kürzlich wurden die Tests des Tesla Model S abgeschlossen. Neu auf dem Prüfstand sind der Jaguar I-Pace, sowie der Hyundai Kona.
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